894702017-12-07Nitrous Ethane-Ethylene Rocket with Hypergolic Ignition, Phase IIActiveApr 2016Apr 2018The Nitrous Ethane-Ethylene Rocket with Hypergolic Ignition (NEERHI) engine is a proposed technology designed to provide small spacecraft with non-toxic, non-cryogenic, high performance, hypergolic propulsion. When passed over a warm catalyst bed, gaseous nitrous oxide and an ethylene-ethane gaseous blend combust instantly. A small 1 N thruster can be designed to provide small satellite propulsion systems with a specific impulse of approximately 300 seconds. Both propellants are self-pressurizing, capable of delivering feed line pressures in excess of 800 psi at room temperature, and 400 psi if cooled to 0?C. For longer duration missions, both nitrous oxide and an ethane-ethylene fuel blend do not require thermal heating to maintain a liquid state, and as such, can be stored on Earth or in space for in-definite periods of time with no parasitic power drain required to maintain a liquid propellant. Compared to other available chemical propulsion systems, a NEERHI system offers a cost effective solution as other hypergolic engines use hydrazine and nitrogen tetroxide which are toxic and dangerous to handle, increasing ground costs. As an added capability, the NEERHI engine has the ability to operate as a monopropellant engine if the catalyst be is heated with a bipropellant reaction, increasing the lifetime of the catalyst bed and reducing heating loads on the engine. The fuel and oxidizer have nearly identical vapor pressure curves, allowing them to be stored in compact common-bulkhead tanks.A NEERHI system is capable of replacing any monopropellant or bipropellant space propulsion system currently used by NASA with a green propellant, self-pressurizing, cold-storable, hypergolic rocket system. The recent MAVEN mission, which uses a propulsion system based off of the Mars Reconnaissance Orbiter, uses a total of 20 hydrazine monopropellant thrusters. A NEERHI system could be adapted to future missions to provide a greater specific impulse with a much lower ground cost due to the low toxicity of the propellants. Future lunar missions, which have historically used an NTO and MMH propellant engine, could use a NEERHI system to not only provide RCS thrust, but the nitrous oxide can also be used to produce a breathable atmosphere for any manned mission. The current technology roadmap for NASA also features a main propulsion unit for the micro-satellite, which could employ a NEERHI engine to provide delta-V maneuvers, station keeping, and even Earth-escape missions. Almost all satellite systems that don't have ion RCS systems could greatly benefit from the integration of a NEERHI unit to reduce the launch cost of the system.<br /><br />A NEERHI system can be used on any commercial satellite system that requires a simple, hypergolic, RCS propulsion unit but wishes to avoid the difficulties encountered when working with a nitrogen tetroxide and hydrazine system. The NEERHI can be used in the emerging cubesat industry, were the primary development teams are university students designing their first space system. A NEERHI engine would provide a safe and affordable system for universities that often have rigorous safety standards, and as such, avoid current hydrazine-based propulsion. In the new field of commercial crew development efforts, the SpaceX capsule currently uses the Draco rocket engine to provide attitude control. The Draco uses an MMH and NTO propellant combination. A NEERHI system could be built to replace these thrusters, and with a supply of Nitrous oxide onboard, future Dragon spacecraft could use the nitrous to produce breathing air instead of bringing along an additional system, taking up mass and space on the craft. A hypergolic and green propellant is the solution sought by all companies to phasing out the use of the dangerous hydrazine-based thrusters, and the NEERHI program could revolutionize the market.44632522In-Space Propulsion Technologies34232.1Chemical Propulsion40832.1.1Liquid StorableSBIR/STTRSpace Technology Mission DirectorateGlenn Research CenterGRCNASA CenterClevelandOHPioneer AstronauticsIndustryLakewoodCOPioneer AstronauticsIndustryLakewoodCOColoradoTherese GriebelCarlos TorrezRobert Zubrin41281Briefing ChartDocumentNitrous Ethane-Ethylene Rocket with Hypergolic Ignition, Phase II Briefing Chart31062https://techport.nasa.gov/file/310625861630500Briefing Chart ImageImageNitrous Ethane-Ethylene Rocket with Hypergolic Ignition, Phase II21850https://techport.nasa.gov/file/2185041930